To connect one optical fiber ribbon to another, it is necessary to prepare the ends of the fibers making up the ribbon so as to obtain optimum operation of the resulting optical link. Conventionally, the ends of the fibers in the ribbon are cut so that their faces to be connected all lie in the same plane orthogonal to their longitudinal axes.
When the ribbons to be connected are placed end to end, with the plane faces to be connected of the optical fibers brought into coincidence, very large amounts of reflection may take place at the interfaces, thereby running the risk of degrading the transmission characteristics of the resulting links.
To mitigate this drawback, when connecting single optical fibers, it is known that the end of the fiber may be caused to have a plane surface that is not perpendicular to the axis of the fiber, with the normal to said surface making an angle of 5.degree., for example, relative to the axis of the fiber. A systematic departure from prior practice is thus created that makes it possible to eliminate parasitic reflections.
Japanese patent application JP-57 24903 describes a method of cutting an optical fiber obliquely, the method consisting in fixing the fiber at two points by means of two clamps, in twisting it about its longitudinal axis, in starting a break by means of a diamond cutter, and then tensioning the fiber while pressing a curved anvil against it until the fiber cleaves. A section plane is then obtained at an angle of inclination that is a function of the torque and of the tension force applied to the fiber.
Such a method cannot be used with a ribbon made up of a plurality of optical fibers disposed parallel to one another in a common protective sheath. It will readily be understood that it is not possible to apply an identical torque to each of the fibers in the ribbon about their respective longitudinal axes. Thus, the section obtained using such a method when applied to a ribbon of optical fibers is not satisfactory: the end faces of the cleaved fibers do not all lie in the same inclined plane.